Mac Mini after replacing HD Drive by new SSD and recovering from Time Machine .
Starts good, but after two hours while I was absent I see error popup
„SecurityAgent was unable to create requested mechanism builtin:prelogin
after clicking OK popup Apparats again and again
Mac mini, macOS 11.6
I solved the problem meanwhile by starting the Mac mini with alt-cmd-r ,
i.e. by recovering from Internet.
after that I deleted the Macintosh HD , installed the OS and recovered from Time Machine .
now everything is ok.
important was to recover from internet after exchanging the Macintosh HD hardware. By that the new device was configured properly.
I solved the problem meanwhile by starting the Mac mini with alt-cmd-r ,
i.e. by recovering from Internet.
after that I deleted the Macintosh HD , installed the OS and recovered from Time Machine .
now everything is ok.
important was to recover from internet after exchanging the Macintosh HD hardware. By that the new device was configured properly.
Not sure giving the info that you have provided, but it sounds like maybe the Mac mini went to sleep and crashed or lost connection with the startup volume.
As a test:
Turn on "Prevent automatic sleeping when display is off" and only allow the display to turn off.
Then just leave the Mac on with the display off and shut down for longer periods of non-use.
If that doesn't help, try using Safe Mode, as per > Use safe mode on your Mac - Apple Support
Or repair the Startup volume in Recovery Mode as per > Repair a storage device in Disk Utility on Mac - Apple Support
Good work, thanks for sharing the fix.
SecurityAgent was unable to create requested mechanism builtin:prelogin
